// 导出页面为PDF格式
import html2Canvas from 'html2canvas'
import JsPDF from 'jspdf'
// https://blog.csdn.net/duangduang94/article/details/124292551 参考文档
export default {
  methods: {
    install() {
      const title = this.codetitle
      const width = 100
      // const height = 60
      const targetDom = document.querySelector('#barcode')
      console.log(targetDom.scrollWidth, 'targetDom.scrollWidth', targetDom.scrollHeight)
      html2Canvas(document.querySelector('#demo'), {
        allowTaint: true,
        scale: 3,
      }).then(canvas => {
        console.log(canvas, 'canvas')
        const contentWidth = canvas.width
        const contentHeight = canvas.height
        const pageHeight = (contentWidth / 592.28) * 841.89
        let leftHeight = contentHeight
        let position = 0
        const imgWidth = width
        const imgHeight = (width / contentWidth) * contentHeight
        const pageData = canvas.toDataURL('image/jpeg', 1.0)
        const PDF = new JsPDF('', 'pt', 'a4')
        if (leftHeight < pageHeight) {
          PDF.addImage(pageData, 'JPEG', 0, 0, imgWidth, imgHeight)
        } else {
          while (leftHeight > 0) {
            PDF.addImage(pageData, 'JPEG', 0, position, imgWidth, imgHeight)
            leftHeight -= pageHeight
            position -= 841.89
            if (leftHeight > 0) {
              PDF.addPage()
            }
          }
        }
        PDF.save(`${title}.pdf`)
      })
    },
  },
}
